Electrochemical analytical control



P. E. EDELMAN. I J ELECTROCHEMICAL ANALYTl-CAL CONTROL.

Patented June 1, 1920.

3 SHEETS-SHEET 1- APPLICATION FILED AUG-I9, L912.

- WITNESSES A INVENTOR.

P. E. EDELMAN'.

ELECTROCHEMICAL ANALYTICAL CONTROL. APPLICATION FILED AUG-l9 I912.'

Patented June 1, 1920,

3 SHEET SSHEET 2.

T I] TREAT- INC- TANK.

as ea FIEHEL WITNESSES INVENTEJRg P. ELEDELMAN.

ELECTROCHEMICAL ANALYTICAL CONTROL.

APPLICATION FILEDYAUG. 19.- 1912.

1,341,790. Patented June 1, 1920.

3 SHEETS-SHEET 3.

SUPPLY REAGENT TREATING FIG-.15 Q

CONS TAN T MIX INVENTOR .features' of the inventionwill be UNITED STAPHILIP E. EDELHAN, OF MINNEAPOLIS, MINNESOTA.

instillation of Letter! Intent.

Tas PATENT OFFICE.

I I ELECTROCHEMICAL ANALYTICAL CONTROL.

f Patented'me 1. 1920.

Application u e August rollers; Serial n6. dam.

methods and means for electrochemical analysis, and it consists in thesteps hereinafter set forth, and in the apparatus for carryin out thesesteps. I

An 0 ject of m invention is to provide a simplified metho of analysiswhich can be carried out b unskilled, as well as skilled, persons, and ywhich the quality, strength, or relative composition of solutions, chembcal compounds, etc., may be readily determined. J

A further object of my invention is to provide a method or process forstandardizmg the product of a chemical process by controlling thequantity of the materials used.

A further ob' ect of 'my invention is to provide means or automaticallyproducing a constant mixture of variable ingredients.

A further object of my invention is to provide apparatus for carryingout the above-name objects.

Other objects and advantagesw'ill appear in the following specification,and the novel articularl pointed out in the appended c aims.

y invention is illustrated in the accompanying drawings, forming part ofthis application, in wh1ch I I Figures 1, 2 and 3 are diagrammatic viewsshowing different embodiments of my invention;

Fig; 4 is a bridge;

Fig. 5 is a detailed view showing an auxiliary circuit which maybecontrolled by the current indicator shown in Fig. 3;

Fig. 6 is a detailed view of certain parts shown in Figs. 1, 2 and'3;

Figs. 7 to 10 inclusive are detailed views of, modified forms ofportions ofthe appa-.

ratus; I

Fig. 11 is a diagrammatic view'showlng the use of the mechanism shown inFig. 5;

detailed view of a slide-wire Fig. 12 is a detailed view of a portion ofa modlficatlon of Fig. 8;

Fig. 13 1s a view showing means for maintaining the apparatus at adesired tempera-- ture; and I Fig. 14 is a view of a modified form ofmeans for maintaining the apparatus at a desired temperature.

Fig. 15 is an assembled view of asuitable embodiment of the apparatusbyway of exambple lllustrating' the use thereof. i a

y invention comprises broadl the comparison of a liquid or solution 0unknown compositionor quality with one of known or standardizedcomposition, orits equiva 'lent, by means of electricalcircuits-havingsuitable 'indicators, variable resistances, currentsupply and current control. I

s an'instance of the application of my invention I may mention thepreparation of bi-sulfite of lime. Milk of lime 18 prepared I a in theusual-manner and sulfur dioxid is passed into the milk of lime which iscon- I tained in a suitable receptacle. Bi-sulfite of lime results andit is necessary for best results to have the correct amount of sulfurdioxid, otherwise there will be an excess of milk of lime which ma causea cloggin like boiler scale. For the right amount 0 sulfur dioxid theliquid should be slightly acid and contain substantially no uncombinedlime. If there is a variation ofthe supply of sulfur dioxid or of milkof lime, the conductivity of the mixture will vary, and this variationopera! s controlling devices which may increase the amount of sulfurdioxid in the manner clearly'set forth hereinafter.

Referring particularly to Fi s. 1, 2 and 3,

I have shown therein a suitab e tube 1 for the standard solution, and asimilar-tube l for the solution to be tested. A slide wire bridge 2 isprovided, and associated with it.

is a galvanometer or current indicator 3. A

calibrated variable resistance 4 is arranged from a battery] (or fromthe generator 7. or any other suitable. source of current, Sincegboth ofthe arms 1 and 1" are simi;

larly affected by the current, it does notmatter, to any noticeableextent, whether the source of current varies, or is of high or lowvoltage.- The battery circuit terminals are indicated in Figs. 1 and 2at 9, but are omitted from Fig. 3 for the sake of clearness.

In Fi 1, the ratio of the unknown liquid in t e tube 1 to the knownliquid in the tube 1 is obtained by moving the sliding contact 5 alongthe calibrated slide-wire 2 until the circuits are balanced. When abalance occurs .then the resistance of the standard solution in the tube1 is to that in the tube 1 as the portion of the slide 2 to the left ofthecontact 5 is to the portion on known composition. The slidablecontact 5' may be set at the point desired or at the point at which abalance is obtained and any variation in the liquid of unknowncomposition will be indicated by the indicator fl. The im ortance ofthis featureis coning the key siderable. se of it is made in testingtreated water in water purification. Any decided variations can beutilized to control the treatment of the water in accordance with thechanges. This may be done manualfly or automatically, as explainedhereina ter.

In Fig. 2 I have provided a current closrent may be cut off from thegalvanometer. In this figure the resistances 4 and4 are preferablynon-inductive. In Fig. 3, I have shown a novel form of slide-wire bridgein which the bridge is condensed into a plurality of lengths 8, theobject bein to secure portability r' the apparatus wit out sacrificingthe accurac possible with a long wire for. the bri ge. In Fi 4 I haveshownmodified forms of thl5)lidg6 wire.

In Fig. 5, a form of the indicator 3 is shownwhich has terminals'aa',adapted to be connected with the bridge circuit, and a separatecircuit-through the pointer 10, contact 12, ri ht contact 13, and leftcontact 13, throug current supply the unknown liquid has less resistancethan the known liquid, or its equivalent, the indicating pointer willswing the contact 12 to one contact as 13, and thatif it isof greaterresistance the contact 12 will swing to the other contact point 13. Ineither case,

6, by means of which the curone of the relays 14 or 14 is operated, andthis, in turn, may control other mechanism as hereinafter set forth. InFi 6, I have illustrated how the tubes 1 an 1 may be constructed to goodadvantage. In this fi ure, C indicates a tube, preferably of g ass andformed in the shape shown. A projection D-is provided wit an o ningcommunicating with a flexible tube having a funnel F. Adjustableelectrodes L and L are suitably mounted in the tube C by means ofsupgorts I, I, provided with thumb flanges J, Q The-supports I and I areheld by ca s K, K, having vents. N, N.- The supports and I are threadedto permit their adjustment. Dischar e openings G, G, are provided. Inthis orm oft e device the l quid or solution is poured into the tube bymeans of the funnel F. The liquid then fills the body of the tube-C andoverflows at G and G. An roducts of electrolysis or ether deposits w ichmi ht washe awa Vents N", as we 1 as vents M, M, in t e caps K, K, serveto revent any possible siphoning action on t e part of the dischargespouts G, G: They also serve to allow the escape of an ssible gas whichmay result from electro ysis. The iquid 'or solution tobe tested finds alevel in the bodv portion C and the tube E, the electrodes L, L, beingcovered by the same.- The operation may be then carried out in themanner already outlined. To clean the apparatus for new tests, thefunnel F can be l rought to the position indicated by dotted mes ousltested will run out. The tube can then be c eaned and refilled with anew solution to be tested.

In place of the tubes 1 and 1, I may substitute suitable. electrodessuch as illuspossibl result from revious usei are-t us at which positionthe solution previ-' trated in Fig. 8. 'These are suitably mounted andadapted'to be inserted in an ordinarycontainer such as a barrel or apot.

of a U ,The electrodes Land L are carried b the shaped orm, theelectrodes, funnel, spouts,

The diagram shows the contact- 'etc., being designated by the samecharacsuitable relays 14 and 14 and,

7". It is evident that when from the battery 7, and bridges the doubleobvious that the a paratus may be adjusted I so that more or ess of thereagent will v at a desire '1 and the outlets flow to the treating tankaccording as more or less is re uired to keep the treated water dstandard. Should the supply remain of a constant composition, neither ofthe contacts 18 or 18 would be closed and conseihuently the reagent flowwould be unaltere In Fig. 12 I have shown how electrodes may be used todetermine the condition of the interior of a boiler. In the figure, 28

representsv a part of a boiler or, tube mto which two electrodes L and Lare screwed by means of insulated bushings 17 and 17".

As precipitation, either natural or that caused b change 0 the,resistance will cause the fact to be indicated. In case of a scaleforming about the'contacts L and L, the apparatus will at once indicatethe fact and serve to tell the operating engineer when to blow off oruse a mechanical scale remover.

In Fig. 13, I have shown means for maintaining a desired temperature.The tubes 1 and 1 in this case are made long to make them sensitive whengood conductors, such as acids, are tested, an are suitably mounted in acommon container P provided with inlet 31 and outlets 32 and 32. Theinlet 31 is preferably located between the tubes 1 and rovided at eachend as shown, in order to insure a uniform supply of the foreign thermicagent. This may be water, cooled or heated as the case may require,steam-if necessary, gases or air, and it should be noted that thethermic agent does not touch or contaminate the material testad or thestandard material. If gases such asammonia areused for cooling. thetubes 1 and 1, the latter maybe sealed in the container P to avoidcontamination. The overflow outlets, G, G, G may be allowed to dischargeinto the samewaste pipes as the outlets 31 and 31, if desired. Qindicates a support for the tubes, and ma be of any .ence of the commonthermic agent, all mem-' "suitable material such as woo protected .withacid-resisting water proof aint.

"In'the modification shown in ig. .14, the

resistance 4 is also placed under the influbers; 1, 1 and 4 beinprotected from contammation with suc -agent. The agents used and theoperation in any case are'simicontact 5, in the a source of electricenergy chemical reagents, results, the

lar to those alread fully described. The orm of a rod, projects throughthe container P and may be moved in or out to adjust the amount ofresistance in circuit.

In Fig. 15 there is assembled the several parts hereinbefore describedvas an exam le of one suitable mode of operation. illustration shows howa constant result can. be attained from'any variable supply with themeans set forth.

It will be obvious'that the present invention may be used in thepreparation of stand:

ard solutions, reagents, medicines, lotions,

mixtures and compositions, as well as-forv the detection and correctionof variations from a desired standard of these and many tainer for oneof said ingredients, means.

for supplying another of said ingredients to sai container, anelectrically operated valve for controlling said supplying means,

said valve, a second source of substantiall constant electric ener ,anelectr1c c1-rcu1t from said last-name source including a 'portion of thematerial in said container,

whereby the current insaid circuit varies proportionately totheconductivity of the material, means in said circuit operated andcontrolled by said current, and means controlled b said last-named meansfor controlling t elcircuit to said valve.

2. An apparatus of the character de- 'scribed comprising, in.combination, a container for material to be treated, variable treatingmeans for said material, a source of electric energy, an electriccircuit from said source including a Wheatstone brid e, one of theresistance arms of said bridge including a portion of the material insaid container, and means for interposing an additional variableresistance in said arm.

, 3. An apparatus of the character described com rising, in combination,a container. for t e ,material to be treated, variable treating meansfor said material, a source of electricenergy, an electric circuit fromsaid source including a Wheatstone or operating bridge, one of theresistance arms of said, I

bridge including a portion of the material in said container, and meansautomatically controlled from said bridge for controlling said treatingmeans.

4. The method of treating a material of variable requirements in orderto obtain a constant resulting product which consists in assing acurrent of electricitythrough sai 'material and var ing the treatment ofsaid material in accor 'ance with the conductivity thereof.

cart.

5. The method of treatin a material of variable requirements in or er toobtain a constant resulting product which consists in passing a currentof electricity from a source of constant electric energy through saidmaterial and utilizing the variations in the flow of said current toeffect the automatic treatment of said material in accordance with therequirements.

6. An apparatus for oontrollin the impurities in a liquid or the like wich comprises electric circuits, of. which the liquid or the like is apart and in which the currents are varied by variations in theimpurities in the li uid, and means actuated by the current variationsfor regulating the impurities.

7. The process of controlling the composi tion of a li uid whichconsists in assing a current of dlectricity throu h the liquid andutiliz'in the variations int ecurrent, caused by variations in thecomposition of the liquid for effecting av compensating treatment of theliquid. 7

8. The process of. controlling the composition of a liquid whichconsists in causin a variation in an electric circuit in accor ance withthe variations of the composition of the liquid and subsequently causingcompensating ingredients to be added to the liquid-by the variations inthe electric cir- 9. The process of controlling the composition of asubstance which consists in automatically regulating the componentsthereof in accordance with the chan es in the electrical conductivityofsaid substanoe. 4

10. An a paratus for controlling the com osition o a substancecomprising means or passing a current of electricity throu h thesubstance and means actuated by the variations of current that areproduced by variations of the composition of the substance forregulating the components thereof. 11. Apparatus for the purposedescribed comprising two substantially identical con+ tainers havingsimilar electrodes and openings, one container carrying a standardportion of material, the other carrying a test portion of material, andthe material in both containers forming part of an electric circuit.

12. Means for including solutions or the like in divided electricalcircuits comprising a plurality of substantially identical containershaving similar electrodes and openings and means independent of thenatural temperature of any one of said containers for controlling thetemperature of all of the containers.

13. Apparatus for including solutions in a balanced electrical circuitcomprising a suitable electrode set adapted to be inserted in saidcircuit and an associated resistance member which represents theelectrical re- -circuitin accordance with the chemical material.

sistance of a standard chemical material,

the whole being compensated for variations in tem ratures.

14. n a device of the type described, a material container, means forvarying the composition of the material to form a roduct and meanscontrolled b I the con ition of the product for maintaimng theuniformity thereof.

15. The herein described method which consists in mixing materials toform a prod not, and in controlling the uniformity of the productthrough .the tendencies of the latter to vary.

16. Apparatus for the purposes set forth which includes a plurality ofidentical solution containers compensated for polariz. tion andtemperature, and an electrical circuit associated therewith andcontaining a resistance member made in the form of a grid consisting ofa plurality of accessible resistance portions having homogeneousconductingterminals in intimate contact therewith at uniform intervals,whereby the electrical balance between said solution containers may bequickly adjusted.

17. In apparatus of the character set forth, means for aiiipmaticallyregulating the components of a process in accordance with variations inthe electrical conductivity of the product thereof.

18. A method for controlling a product which consists in utilizingelectrical variations therein to operate electrical means which consistsin treating a chemical material, including a portion thereof in anelectrical circuit, subjecting sa d portion to the influence of aseparate external thermic agent. and causing said portion to affect saidpurity of said 21. The method of analysis which comprises dividing asubstance into a plurality of containers surrounded by a. commonexternal thermic agent insulated from electrical contact with saidsubstance, treating the divided portions, and including the treatedportions in an electrical circuit which is not affected by thetemperature or ionization of said portions unless the chemicalcomposition of at least one of said portions varies from a desiredstandard.

22. Apparatus for the purposes set forth comprisinga reagent control andoperative means therefor regulated by fluctuations in an electricalcircuit.

23. The system which comprises the plac ing of a chemical substance inrelation with electrodes, the balancing of the electricalcharacteristics of said substance against a resistance member which hasbeen made equivalent to a standard portion of said said fluid in saidelectrical circuit which function onl when the chemical nature of thefluid wit in one of said test portion containers differs from that inthe other.

25. As a testing machine, means to treat a plurality of test portions, ajacket about said test portions whereby a thermicagent external to andseparated from said test portions may bring all of said test portions tothe same temperature contemporaneously, and an electric circuitembracing said test portions. 26. Ap comprising electrodes-which arecapable of being inserted in a chemical supply, a compensated standardassociated therewith-for direct comparison, and an electrical circuit inrelation therewith and containing a current consuming device whichfunctions onl when the chemical nature of said supply dif fers from thatrepresented by said standard. 27. Apparatus for the purpose set .forth'comprising standard and test portions, auxiliary resistances which maybe substituted I for said portions, external ,insulatedmeans forcontrolling the temperature thereof, and

' indicating and control devices connected thereto and operated only byfluctuations in the chemical nature of one of said portions which isunder test, whereby the supply from which said' test portion is takenmay be controlled.

28. Apparatus for the purposes set forth comprising electricalcontrolling means operated by a circuit including a portion of thematter to be controlled.

29. Apparatus for chemical testing comprising a primary divided circuitincluding a portion of the substance under test, a standard metallicresistance member re resenting a standard portion of a stan ard strengthof the substance under test connected in said circuit, electrical meansconnected therewith which function in accordance with fluctuations inthe portion under.

fiiestiwhich are caused by the chemical comgs' 'ps'rtion thereof, and anamplifier associated cffithijsaid electrical means, said amplifiercontainers having simi paratus for the purposes-set-forth operatingmeans to control additional units 0 the substance under test.

. 30. Apparatus for the purposes set forth.

comprising an electrical ,circuit adapted to include desired portions ofmatter, indicatmg means, and means electrically connected to saidportions and operated b fiuc- I tuations in the conductivity of onetiereof v to automatically control the said matter.

- 31. The method for the purposes setforth which consists in lacing asubstance in electrical relation wit 1 a resistance representing astandard substance and comparing the resistances of the two, the wholebeing under thecontrol of a common and independent thermic agent.

- 32. -Apparatus of the class specified comprising' means for includinguniform portions of solutions 'in a divided circuit, a

compensated resistance member equivalent to astandard portion, and abalancing member "com rising a resistance element pro- .vided wth-aplurality of conducting sup ports any of which supports may beconnectedto said circuit.

-' -33. Apparatus for the purposes set forth consisting of a pluralityof interchangeable ar electrodes and a common jacket through which "athermic agent may be circulated, and, an electrical clrcuit in, relationtherewith.

34. Means for introducing a liquid as-a part-of an electrical circuit"com rising a conduction tube having flexible filling and emptyingmealis, adjustable electrodes, and means for-preventing deposits. 35.Apparatus for introducing a solution as a part of an electrical circuitcomprising a conduction tubevprovided with a combined filling andemptying means, suitable electrodes, and vents.

36. Apparatus for-the purposes set forth comprising electrodes, acombined means for both introducing and withdrawing test portions, and athermic control therefor.

37 Apparatus for the purposes set forth comprislng a plurality ofelectrodes,'aux

iliary means for maintaining a uniform test portion therebetween, anexternal thermic bath for said test portion;adjustab1e to anytemperature regardless of the natural temperature of said test portion,and elec-- trical circuits in relation to said electrodes. 38. Apparatusfor the purposes set forth comprising means to include test portions inan electrical circuit, means insulated therefrom to control thetemperature thereof, primary means operated by the said circuit, andamplifying means in relation. therewith;

39..A method for the purposes set forth which comprises maintaining achemical supply in a desired relation withv a standard under compensatedconditions and causing variations in the'conductivity of the said leesupply to operate controlling means there 40. The system for thepurposes set forth which consists in supplying an electrical currentthrough a plurality of closed solution tubes whlch are sub'ect to thecommon thermic influence of an e ectrically insulated I prising l aplurality of close thermic agent, and utilizing the said current tooperate a relay device.

4 1'. A method of testing which consists in placing a standard solutionportion in a container, placing a test portion from asupply in anexactly similar container, heating or cooling'both of said containerscontemporaneously, compensating for the electrometive force due togaseous decomposition products, and determining the relativeconductivity of the portions within said containers.

42. Themethod for the purposes set forth which consists in placingspaced electrodes intomatter to form a test portion, compensating fornon-chemical factors which influence'the conductivity. of thesaidportion,

detecting the chemically caused conductivity, and magnifying the resultthereof.

43. Apparatus of the class s iecitied ('omconduction tubes ving a commonthermic jacket, a primary electrical circuit includin said tubes, asecondary circuit controllcdiy the said primary circuit, andelectro-mechani cal means operated by the said secondary circuit.

Signed this 14th day of August, 1912, at Minneapolis, Minn.

PHILIP E. EDELMAN. Witnesses:

Mn'rnn I. EDELMAN, Anxn'rra Man'rnwson,

